What does the manufacturer of the furniture recommend?

It's a gl lazboy and I just got a reply from them: they don't endorse any particular conditioner.

When I walk in to a La-Z-Boy gallery, I do not smell leather, so I'm guessing that it is all fully protected.

To the best of my knowledge, La-Z-Boy only carries fully protected leathers, so a conditioner may not have much effect on that leather.

That's interesting. It's one of the big chairs and was $1200 if that helps.